We propose a 5-year randomized controlled trial that targets methadone maintenance treatment (MMT) programs in China. Applying the principles of combination prevention, the proposed intervention (MMT CARE) integrates psychosocial and behavioral components into a pharmacological framework for methadone maintenance. A total of 68 MMT clinics will be randomly selected from four provinces. From each clinic, 6 service providers and 36 clients will be recruited, totaling 408 providers and 2,448 clients in the study. The 68 clinics will be randomized to: 1) a MMT CARE intervention group, or 2) a control group (34 clinics each). Service providers who complete the training will conduct three individual motivational enhancement sessions with clients. Efficacy of the intervention will be evaluated at baseline and at 3, 6, 12, 18, and 24-month follow- ups. The outcomes for service providers will be measured by: 1) improved adherence to MMT protocols; 2) decreased prejudicial attitudes; 3) increased interaction with clients; and 4) increased communications with clients about risk reduction. The outcomes for clients will be measured by: 1) improved treatment adherence/retention; 2) decreased concurrent drug use; 3) increased motivation for behavior change; 4) improved mental health; 5) increased positive support; and 6) reduced HIV risk behaviors.